A Simple Photonics-Based Measurement Method for Microwave DFS and AOA

This article put forwards a simple microwave photonics measurement method for microwave doppler frequency shift (DFS) and angle of arrival (AOA), which obtains the information conveniently and precisely by comparing the frequency and phase shift between two channels signals. The DFS direction can be judged more intuitively thanks to the introduction of the reference signal. The system uses two parallel dual parallel Mach-Zehnder modulators (DPMZMs) for carrier suppression single-sideband (CS-SSB) modulation. A proof-of-concept experiment was taken, showing that during ±100 kHz, the DFS measurement error is <±0.1 Hz over a 40 GHz frequency range as well as power sensitivity is down to −50 dBm. What is more, the measurement error of AOA is < ±1° from 0° to 90°. This simple system acquits excellent width band performance without the optical filter, providing a reliable and more conducive to human-computer interaction solution for future measurement and sensing applications.